The ultrasonic apparatus as is set forth in the opening paragraph is known from U.S. Pat. No. 6,508,774 B1. The known apparatus comprises a patient accommodation means, notably a patient support means, in the form of a patient support table on which a patient to be treated is to be positioned. The known apparatus is suitable for carrying out therapeutic procedures by means of application of high energy ultrasonic waves. For this purpose the known apparatus comprises a first reservoir with a transmission medium for supporting a portion of a patient. In the known apparatus deaerated water is used for the transmission medium for conducting the ultrasonic waves substantially without dissipation to the portion of the patient. The support means of the known apparatus further comprises an ultrasonic wave source disposed in the first reservoir and having an emitting surface oriented towards the portion of the patient. In order to couple the ultrasonic waves emanating from the first reservoir to the patient the known ultrasonic apparatus further comprises a second reservoir comprising a coupling medium (gel) providing a low reflectivity interface and having a contact surface with the portion of the patient. During use, the second reservoir is positioned between the first reservoir and the portion of the patient.
In an alternative embodiment of a known high energy focused ultrasonic treatment, a portion of a patient, notably a breast, may be disposed in the first reservoir. In this case the portion of the patient, notably the breast, may be arranged with a second reservoir filled with a coupling medium, the said second reservoir being arranged around the portion of the patient, for example like a wearable.
It is acknowledged in the art that air bubbles may occur at various contact surfaces or within the transmission medium present on the first reservoir. Such contact surfaces may be formed in different circumstances. For example, a suitable contact surface may be formed between the transmission medium present in the first reservoir and the portion of the patient. It is noted that it is possible that the portion of the patient is disposed in the first reservoir, or that the portion of the patient if supported by the first reservoir. The first situation may correspond to a treatment of a substantially isolated part, like a female breast, whereas the second situation corresponds to a conventional, notably abdominal, treatment. Additionally, it is possible that a second reservoir comprising a suitable coupling medium is provided between the transmission medium of the first reservoir and portion of the patient. In this case air bubbles may occur also at a contact surface between the transmission medium and the second reservoir and/or between the first reservoir and the second reservoir.
Also, the air bubbles may occur in the transmission medium, notably due to cavitation processes. It is acknowledged that any air bubble present on a path of an ultrasonic wave substantially deteriorate the therapeutic effect of the treatment, notably high intensity ultrasonic treatment. Moreover, air inclusions in the area of the contact surface, between the second reservoir and the patient may cause severe burns to the patient skin. It is a general practice to reposition the patient, frequently several times, in order to control the air-free interface between the second reservoir and the patient, because presence of air bubbles may distort an ultrasonic field resulting in erroneous treatment.
It is a disadvantage of the known apparatus in that sufficient time is lost due to repositioning of the patient on one hand, and in that the outcome of the treatment may be dependent upon the confidence level with respect to the absence of any air bubbles at the contact surface.